Dynamic changes in salivary cortisol and secretory immunoglobulin A response to acute stress

Psychological stress leads to the secretion of cortisol. While this psychoneuroendocrine response helps to maintain physiological as well as psychological homeostasis under stress, exaggerated release of cortisol can suppress aspects of immune function and have negative effects on health. The present study set out to investigate the dynamic changes in salivary secretory immunoglobulin A (sIgA) and cortisol before and after acute stress, and to analyse the relationship between sIgA and cortisol trend. Thirty-five healthy subjects took part in this study. All subjects underwent an acute stress test (mental arithmetic task). Salivary cortisol and sIgA responses were assessed repeatedly before the stress test, immediately after the stress test and 20 min after the stress test. The levels of salivary cortisol and sIgA both significantly increased after the acute mental arithmetic challenge. However, the increase of sIgA is transient; the sIgA fall was significantly correlated with the cortisol rise during the 20 min after stress (r = 0.569, p < 0.001). These results may help determine the timing of effective intervention in order to reduce the hypersecretion of cortisol and improve mucosal immune function.